CONICET | Buscador de Institutos y Recursos Humanos

Sheep brucellosis is caused by Brucella ovis and B. melitensis. Control strategiesfor this disease include periodic diagnosis through serological tests and/orbacteriological cultures, as well as the culling of positive animals. Application ofBrucella melitensis Rev-1 vaccine is recommended when prevalence is high.However, this attenuated vaccine strain presents significant drawbacks includingthe development of antibodies that interfere with serodiagnosis, and its virulencein humans, among others. Therefore, it is important to develop new safe andeffective vaccines against ovine brucellosis. Outer Membrane Vesicles (OMV)from Gram-negative bacteria have been used in the development of acellularvaccines against numerous infectious diseases. In this study, we assessed theimmunogenicity of OMV from B. ovis (strain Reo 198) with the aim of evaluatingtheir potential as an acellular vaccine. For this purpose, B. ovis was cultured intryptic soy broth supplemented with 0.5% yeast extract for 72 hours. OMV wereisolated from the cell-free culture supernatant through ultracentrifugation. Theprotein content of the OMV fraction was determined using the bicinchoninic acidmethod, and the size of the isolated OMV was measured using Dynamic LightScattering (DLS). DLS analysis demonstrated that OMV have a hydrodynamicdiameter of 60 nm. To assess whether the B. ovis OMV antigens are recognizedby serum antibodies from naturally infected sheep, an indirect ELISA assay wasconducted using serum samples from both diseased and healthy animals. Inanother experiment female BALB/c mice were immunized by intramuscular routewith 5 ug of OMVs, 5 ug of OMV plus 10 ug c-di AMP (adjuvant), or saline solutionat 0 and 30 days. Sera samples were obtained at 21 and 45 days for the firstimmunization to determine specific antibody production by indirect ELISA. Thelevels of anti-OMV IgG in the sera of infected sheep were significantly higher thanthose of healthy animals (p

enviar mensaje